Pesticidal omicron, omicron-dimethyl-omicron-(2-[or 3-] methoxy-4-cyanophenyl) phosphorothioate



United States Patent 6 3,301,749 PESTICIDAL 0,0-DIMETHYL-O-(2-[0R 3-]ME- THOXY 4 CYANOPHENYL) PHOSPHORO THIOATE Michihiko Sakai, MasayukiKato, and Yasuo Sato, Kyoto, Kazuo Konishi, Osaka, and Tetsuya Okutani,Hyogo, Japan, assignors to Takeda Chemical Industries, Ltd., Osaka,Japan No Drawing. Filed Nov. 29, 1963, Ser. No. 327,086

Claims priority, application Japan, Dec. 1, 1962, V

37/ 54,255 12 Claims. (Cl. 167-30) The present invention relates tonovel pesticidal composition containing phosphoric acid esters and totheir use for agricultural, veterinary and sanitary purposes. Moreparticularly, the said phosphoric acid esters are those of the formula:

wherein R and R stand for lower alkyl, and R stands for lower alkoxy oraryl.

The phosphoric acid esters of the above-mentioned Formula I have theeffect to kill harmful pests such as various insects, acari andnematodes, with low toxicity to warm blooded animals, and, therefore, bya suitable choice of concentration of the phosphoric acid esters appliedto pests and of the application method, the compounds are useful for newtype pesticides.

There have been reported many kinds of pesticides, but only a few ofthem are actually utilized for agricultural, veterinary and sanitarypurposes, because most of them can not be used without risk of harm towarm blooded animals, or the agents have only low effect to pests.

Although many attempts have been made to overcome the aforesaidshortcomings and other disadvantages, none, as far as the presentinventors are aware, has entirely been successful when applied topractical use.

The present invention provides a series of new phosphoric acid esters ofthe above-mentioned Formula I, having a remarkable pesticidal activityupon application of a small quantity of compound to pests.

It is an object of the present invention to provid pesticides which arefree from the above-mentioned shortcomings or disadvantages. Anotherobject is to provide new phosphoric acid esters.

The present invention also contemplates providing methods forpreparation of the said phosphoric acid esters. Among the furtherobjects of th present invention is the provision of pesticides whichcontain the phosphoric acid esters (I), and their use in killing pests.

Other objects and advantages will become apparent from the followingdescription taken in conjunction with the examples.

The phosphoric acid esters (I) of this invention can be synthesizedthrough the reactions shown in the following reaction formula;

sented by R is lower alkyl as mentioned above. The two alkyl groupsrepresented by R or R may be the same as or different from each other.

The aryl group represented by R may, for example, be phenyl orsubstituted phenyl, as the substituent, there may be mentioned alkylsuch as methyl, ethyl, propyl and isopropyl, and halogen such aschlorine and bromine.

As previously described, the phosphoric acid esters of the presentinvention may be provided by the reaction as shown in the abovementionedreaction formula.

The reaction may be carried out in the presence of a suitable solvent.The solvent may, for example, be water, alcohols such as methanol,ethanol, etc., ketones such as acetone, methylethylketone, etc.,hydrocarbons such as benzene, toluene, xylene, etc., esters such asethyl acetate, amides such as dimethylformamide, or a mixture consistingof two or more of these solvents. The reaction may be promoted by theaddition of such organic bases as pyridine, triethylamine,dimethylaniline, or such alkali as carbonates, bicarbonates, metalhydroxides such as sodium hydroxide and potassium hydroxide, to thereaction system. The reaction may be effected at room temperature (15 to30), and may also be controlled by heating.

The following list sets forth typical phosphoric acid esters prepared bythe method of the present invention, which are useful as activeingredients in the pesticidal compositions according to the presentinvention:

( 1) 0,0-dimethyl-O-(2wmethoxy-4-cyanophenyl) phosphorothioate (2)0,0-dimethyl-O-(3-methoxy-4-cyanophenyl) phosphorothioate (30,0-diethyl-O- 3-ethoxy-4-cyanophenyl) phosphorothioate (4)0,0-diethyl-O-(2-methoXy-4-cyanophenyl) phosphorothioate 5 O-ethyl-O-2-ethoxy-4-cyanophenyl) paratolylphosphonothioate (6) O-ethyl-O-2-methoxy-4-cy anophenyl) phenylphosphonothioate (7) O-methyl-O- 3-rnetho-xy-4-cyanophenyl) paratolylphosphonothioate (8) -O-methyl-O-2-methoxy-4-cyanophenyl) paraanisylphosphonothioate (9) 0,0-diethyl-O-(2-methoxy-6-cyanophenyl) phosphorothioate 10) 0,0-dimethyl-O-(Z-cyano-S-methoxyphenyl phosphorothioate 1 1 O-ethyl-O-(2-methoxy-6-cyanophenyl) phenylphosphonothioate 12) O-methyl-O-(2-methoxy-6-cyanophenyl) parachlorophenylphosphonothioate 130,0-dimethyl-O- (2-methoxy-6-cyanophenyl phosphorothioate (14)0,0dimethyl-O- 2-ethoxy-4-cyanophenyl) phosphorothioate 15)0,0-diethyl-O- (2-ethoxy-4-cyanophenyl) phosphorothioate 16)0,0-diethyl-O- 2-cyano-4-methoxyphenyl) phosphorothioate 17) O-ethyl-O-(2-cyano-4-methoxyphenyl phenylphosphonothioate 18) 0,0-diethyl-O-(Z-cyano-S-methoxyphenyl) phosphorothioate (19) 0,0-diethyl-O-3-methoxy-4-cyanophenyl) phosphorothioate (20) 0,0-diethyl-O-(4-methoxy-3 -cyanophenyl) phosphorothioate (21)0,0-dimethyl-O-(2-methoxy-5-cyanophenyl)phosphonothioate In practice,and to realize the desired activity, the pesticides of the presentinvention are advantageously applied to harmful pests in the form of thecompositions such as dust, emulsion, suspension or solution. In otherwords, the pesticidal compositions of the present invention compriseessentially at least one active compound (phosphoric acid ester)represented by the above-mentioned Formula I together with a suitablecarrier (e.g. extender and/or conditioning agent) of the type commonlyemployed for the carriers of a known pesticidal agent. It is notintended, in this respect, that the present invention be limited to anyspecific proportions of active ingredient(s) (I) and adjuvant.

The compositions may be readily prepared ab initio or may e.g. be in theform of concentrates comprising active ingredient (I) with only a minoramount of an adjuvant, e.g. a surface active agent. Such a concentrateis economical as regards transportation, storage and the like, and mayeasily be admixed-prior to usewith additional adjuvant to give thedesired concentration of the active ingredient when it is applied. Theadjuvant may be .selected depending on pests to be treated, propertiesof active ingredient and other adjuvant to be used together, andconditions of use.

Thus, if both the active ingredient and adjuvant(s) are water-soluble,the composition may be applied in the form of an aqueous spray. If, forexample, a water insoluble adjuvant is employede.g. if the compositioncomprises a water-insoluble adjuvantthe composition may be applied as anaqueous dispersion. It is also possible e.g. merely to mix the activeagent, in powder form, with a powdery adjuvant and to use the mixture(dust). Or, the powdery mixture may be suspended in water or in an oil,such as gasoline, kerosene, etc. which, upon mixing with water, formse.g. an oil-in-water emulsion containing the active ingredient. When thecompositions are used in dust form, the adjuvant (or diluent) may e.g.be talc, clay, diatomaceous earth, lime, calcium sulfate, kaolin and thelike.

When the compositions are used in the form liquid, the adjuvant(diluent) is e.g. water, an aqueous solvent, a volatile or non-volatileorganic solvent, e.g. an alcohol such as methanol, ethanol, a ketonesuch as acetone, methylethylketone, an ether such as dioxane,tetrahydrofuran, an aromatic hydrocarbon such as benzene, toluene,xylene, a halogenated hydrocarbon such as chloroform, carbontetrachloride, an ester such as ethyl acetate and oil, the compositionasafore-indicated-taking the form of a solution, emulsion or suspensiondepending on the nature of the materials employed.

The new pesticidal compositions may further contain wetting agents,dispersing agents and emulsifiers such as a suitable surface activeagent e.g. polyoxyethyleneglycolethers, polyoxyethyleneglycolesters,polyoxyethylene derivatives of sorbitan monolaurate (monooleate,monostearate), polyoxyethylenealkylarylether, alkyl sulfonate, alkylarylsulfonate, alkyl sulfosuccinate. They may also contain adherent orsticking agents, and also other agricultural chemicals, e.g. fungicides,vermicides, all these materials being considered adjuvants.

It is within the scope of the present invention to employ otheradjuvants than those hereinbefore mentionede.g. solid or liquiddiluents, emulsifiers, dispersants, surface active agents orotherwisethose already mentioned being merely illustrative.

The essence of the present invention does not reside in any specificadjuvant but in a composition consisting essentially of at least onecompound of the Formula I and an appropriate pesticidal adjuvant whichdoes not prejudice the activity of the composition.

Generally speaking, an effective amount for killing harmful pests issatisfied with the following quantitative relationships.

A dust or oil composition for direct application to pesticides maycontain from 0.1 percent to percent or more of the active ingredient(s)by weight. When the composition is prepared for actual use in the formof sprays or more dilute dusts, the content of the active ingredient(s)may vary from about 0.001 percent to as high as 0.1 percent by weight,the balance of the composition being one of the diluents and/or surfaceactive agents (adjuvants) previously mentioned.

Content of the active ingredient in an aqueous dispersion may similarlyvary from a very low percentage, e.g. 1 percent by weight, where thedispersion is applied directly to pests, to a relatively highpercentage, e.g. percent by weight, where the dispersion is employed asa concentrate, the balance in each case being constituted by an adjuvantor adjuvants.

Examples of pesticidal effect upon various pests by application of thephosphoric esters (I) are set forth as follows:

EXAMPLE 1 Test for killing houseflies (Musea domestica) Acetonesolutions of the respective test compounds set forth in the followingtable were prepared, and a definite amount of each of so preparedsolutions was dropped on the back of thorax of housefiies. After 24hours, the number of killed insects was counted. The results are shownin the following table:

EXAMPLE 2 T est for killing Chinese bean weevils (Callosobruchuschinensis) One cubic centimeter of each of acetone solutions of the testcompounds set forth in the following table was poured into a Petri dishto cover the inside bottom of the dish. After the solvent was evaporatedby airing gently, Chinese bean weevils were set free in the Petri dish.24 hours later, the number of killed insects was counted to calculatethe lethal concentration (LC Test compound:

O-dimethyl-O- Z-methoxy- 4-cyanophenyl phosphorothioate O-ethyl-O-2-methoxy-4-cyanophenyl phenylphosphono- LC percent thioate0.00125-0.0025 O, O-diethyl-O- 2-methoxy-4-cyanophenyl) phosphorothioate0.0006250.000125 0,0-dimethyl-O- 3-methoxy-4-cyanophenyl)phosphorothioate EXAMPLE 3 (1) Test for killing soybeanaphids (Aphis glycines) 10% emulsion of each of the test compounds setforth in the following table was prepared. The test solution so dilutedas indicated in the table was sprayed over soybean plants infested withsoybean aphids at the rate of 20 cubic centimeters per plant. Survivalrate was calculated after 2 days to obtain the result shown in thetable.

but still the remaining were observed alive Decrease of the number ofsoybean aphids befofe spraying the test solutions was hardly observed L:

Concentration of Test compound test Result compound, percentO-ethyl-O-(2-methoxyl-cyanophenyl) phenyl- 0.05 phosphonothioate. 0.025

0.0-diethyl-O-(Z-methoxy-l-eyanophenyl) 0. phosphorothioate. 0.025

0,0-dirnethyl-O-(3-methoxy-4-cyanophenyl) 0. 05 phosphorothioate. 0.025

0,0-dlmethyl-0-(2-methoxy-4-cyanophenyl) 0.05 phosphorothioate. 0.025

Malathion 1 0.05 0.025

See footnote, column.-

(2) Test for residual action of test compound Mortality rate of soybeanaphids transferred on soybean Concentraplants Test compound tion of testwhich compound had been sprayed the test solution two days before,percent Control- *1l6. 7 0,0-dimethyl-O-(B-methoxy-l-cyanophenyl) 0. 02100 phosphorothioate. 0 01 100 v 0.005 100 Malathion 1 0.02 *80 0.01*-l30 0.005 *-253 1 See footnote, column 11. *Increased.

EXAMPLE 4 (1) Test for killing Kanzawahadani (Tetranychus kanzawai)emulsion of each of the test compounds set forth in the following tablewas prepared. The test solutions diluted with water to 0.05% of therespective test compounds Were sprayed over soybean plants infested withKanzawahadani at the rate of 20 cubic centimeters per plant. Survivalrate was calculated after 2 and 7 days to obtain the result shown in thetable. The marks, and have the same meaning as those in Example 3,respectively.

See footnote, column 11.

(2) Test for ovicidal action to egg of Kanza'wahz'zdani [The result wasobserbed 7 days after spraying] Concert: tration of Ovicidal Testcompound test comrate;

pound, percent percent Control 0 0, 0-diethyl-O-(2-metl1oxy-4-cyanophenyl) 0.1 phosphorothioate. 0. 5 100O-ethyl-O-(2methoxy-4-cyanophenyl) O. 1 100 phenylphosphonothioate. 0.05 100 Pestan 2 0. 1 100 0.05 100 See footnote, column 11.

EXAMPLE 5 Test f r killing nematoa'a 10% emulsion of each of the testcompounds set forth in the following table was prepared. The preparedemulsion was diluted with water to 0.05% of the test compound. 2milliliters of thus obtained test solution were put in a glass dish, andthen nematoda (Rhabditoides sp.) was put therein. The dish was coveredand kept standing at 25 C. for 72 hours.

Rate of killed Test compound: nematoda, percent 0,0-dimethyl-O-2-methoxy-4-cy-anophenyl) phosphorothioate 100 Oethyl-O-(2-methoxy-4-cyanophenyl) phenylph-osphonothioate 1000,0-diethyl-O-(2-methoxy-4-cyanophenyl) phosphorothioate 1000,0-dimethyl-O- (3 -methoxy-4-cyanophenyl) phosphorothioate 100 EXAMPLE6 Test for killing matured larvae of rice stem borers- (Chilosuppressalis) Acetone solutions (50 'y/ g.) of the respective testcompounds set forth in the following table were prepared. Each of thetest solutions thus prepared was applied on the backs of thorax of ricestem boners. After 24 hours, the rate of killed nematoda was observed.

Marks in the table have the same meaning as those in Example 5.

Rate of killed Test compound: nematode, percent0,0-dimethyl-O-(Z-methoxy 4 cyanophen- Test for killing soybean aphids(Aphis glycines) 10% emulsion of each of the test compounds set forth inthe following table was prepared. The test emulsion diluted. with Waterto the concentration as in the table was sprayed on soybean plantsinfested with soybean aphids at the rate of 20 cubic centimeters perplant. After 48 hours, the rate of killed insects was observed to obtainthe result shown in the table.

Ooncen- Rate of tration of killed Test compound test corninsect,

pound, percent percent 0, O-diethyl-O-(2-methoxy-4-cyanophenyl) 0.02 100phosphorothioate. 01 94.1 0 005 80.1 0,O-dlmethyl-O-(Z-methoxy-4-cyanopheny1) 0 100 phosphorothioate. 0 025 100O, O-dimethyl-O-(3-methoxy-4-cyan0phenyl) 0 01 100 phosphorothioate. 0.005 100 O-ethy1-0-(2-methoxy-4-cyanophenyl) O. 05 100phenylphosphonothioate. 0. 025 100 EXAMPLE 8 (1) Test for killing greenrice leaf hoppers (noephotettix apicalis cincliceps) and white backplanhopp'er (Sogata furcifera) Solution containing each of the testcompounds set forth in the following table was prepared. In thusprepared solution, stems of rice plants were dipped, respectively. Afterdryness by airing, each stem was put in glass tube, and then testinsects (5 males, 5 females) were put in each glass tube. 24 hourslater, the rate of killed insects was observed.

Rate of killed insect, Concentrapercent Test compound tion of testcompound Green rice White back leaf hopper planhopper Control(non-treated) 0 0 0 0,0-dirnethyl-O-(2-rnethoxy 0 025 100 100eyanophenyl)phosphorothi0- 0 0125 100 100 ate. 0 00625 95 1000,0-diethyl-O-(2-meth0xy4- 0 025 100 100 cyanophenyl)phosphorothio- 0.0125 100 100 ate. 0. 006 100 100 0 (103 90 100 0 0015 90 100 Sevin 3 0025 100 100 0 0125 100 100 0 006 100 30 0 003 50 0 0015 0 Malathion 1 0025 100 100 0 0125 100 100 0 006 100 100 0.003 100 90 0.0015 100 50 Seefootnotes, column 11.

(2) Test for residual action of test campounds to green rice leaf hopperand white black planhopper The test solution containing each of thecompounds set forth in the following table was sprayed over rice plants.The stems were cut off from the treated plants after 3, 5 and 7 days,respectively. The cut stems were put in cages together with the insects,and after 24 hours, the rate of killed insects was observed to obtainthe result 8 EXAMPLE 9 Test for killing rice stem borers (Chilosuppressalis) 10% emulsion of each of the test compounds set forth inthe following table was prepared. Then the emulsion was diluted to theconcentration as shown in the table. The resulting solution was sprayedon rice stem borers Survival rate was calculated after one week toobtain the results shown in the table:

Concentra- Survival Test compound tion of test rate,

compound, percent percent 1 Control 860,0-dimethyl-0-(Z-methoxy-4-cyanophenyl) phosphorothioate 0. 05 7. 3Ethyl parathion 8. 1 Control 26. 4 0,0-dimethyl-O-(B-methoxy--cyan0phenyl) 0.05 9. 4 phosphorothioate. 0. 025 14. 6 Ethyl parathion 40.025 2. 8 0 Control 48.8 0,0-dimethyl-O-(Z-ethoxy- -cyanophenyl) 0.051.0 phosphorothioate. 0. 025 6. 9 Ethyl parathion 4 0. 05 3. 3

See footnote, column 11. 25 EXAMPLE 10 Test for killing citrus red mites(Paratetranychus citri) [Test method was referred to that in Example 4]EXAMPLE 10 3O Decreasing rate of the Concentratest insects, percent Testcompound tion of test compound,

percent 2 days 7 days later later Control 25. 5 33. 00,0-diethyl-O-(2-methoxy-4- 0.05 93. 9 99. 1 cyanophenyl) phosphorothio-O. 025 85. 8 98. 8 ate. 0.0125 74. 4 97. 4

EXAMPLE 11 Test of toxicity to white mice Each of the test compounds wasadministered orally to four-week old male white mice and the mortalitywas observed after 24 hours to obtain median lethal dose (LD). The LD-50values are shown in the following salis) Test compound:

ao (mg/kg.) 0,0-dimethyl-O- Z-methoxy-4-cyanophenyl) phosphorothioate4200 0,0-dimethyl-O- 3 methoXy-4-cyanophenyl) phosphorothioate 18000,0-diethyl-O-(2-methoXy-4-cyanophenyl) phosphorothioate 73 EXAMPLE 12Test of toxicity to adult houseflies (Musca domestica) and to maturedrice stem borer larva (Chilo suppresshown in the table. salis)Concentra- Rate of killed insect, percent d tion of test Test insectTest com oun eompoun p percent 7 8 days 5 days 7 days later later laterControl a 0 0 0 Green rice leaf 0,o-dietlhyl-gl-(znethoxyi-cyanophenyl)0. 05 100 15 ho er. hos oro ioa e.

pp M lath ion 1 0.05 108 68 48 White back h h t 100 100 100 a ho er. hosorot ioa e. p n pp M lath ion 1 0.05 100 75 See footnote, column 11.

The acetone solution of each of the test compounds was applied on theback of test insects using micrometerdriven syringe. After 24 hoursmortality was observed to obtain median lethal dose (LD-SO) shown in thefollowing table.

In the table, the compounds are represented by the corresponding numbersshown below:

0,0-dimethyl-O- 2methoxy-4- cyanophenyl) phosphorothioate I0,0-di1nethyl-O-(3-rnethoxy-4-cyanophenyl) phosphorothioate II0,0-diethyl-O- (2methoxy-4-cyanophenyl) phosphorothioate III O-ethyl-O-2-meth-oxy-4-cyanophenyl phenylphosphonothioate IV0,0-diethyl-O-(2-methoxy-6-cyanophenyl) phosphorothioate V0,0-dimethyl-O- 2-rnethoxy-6-cyanophenyl) phosphorothioate VIQo-dimethyl-O- (2-ethoXy-4-cyanopheny1) phosphorothioate VII0,0-diethyl-O- 2-ethoxy-4-cyanophenyl) phosphorothioate VIII0,0-diethyl-O- 2-cyano-4-methoxy-phenyl) phosphorothioate IXO-ethyl-O-(2-cyano-4-methoxyphenyl)phenylphosphonothioate X HousefiiesRice stem Test compound LDao (r g-lg.) borer LD50 (Ma/e) I 6. 2 1o 3.15-10 5. 6 50. 7. 6 50 200 50 200 so 30. s 10 X I Parathion m. EPN uMalathion DEP See footnote, column 11.

EXAMPLE 13 Test of residual action to soybean aphids (Aphis glycines)The emulsified-liquid of each of the test compounds was sprayed to thepotted seedling of soybean and after 'two days Wingless females weretransferred on the leaves of the sprayed plants. The mortality oftransferred population was observed two days after the translocation.The result is shown in the following table.

The numbers representing the compounds in the table are the same ones asin the Example 12.

See footnote, column 11. Increased.

EXAMPLE 14 Test of ovicidal action to the eggs 0 Kanzawahadani(Tetranichus kanzawai) 15 III The numbers representing the compounds inthe table are the same ones as in the Example 12.

Ovicidal rate, percent Concentration Test compound of test compound,percent Pestan 2 See footnote, column 11.

EXAMPLE 15 Test of residual action to adult female greeru riceleafhopper (Nephotettix apicalis cincliceps) After spraying emulsifiedliquid of each of the test compounds to potted rice plant, the stemswere separated and put in the cage with test insects to observe after 24hours the mortality of insects caused by the residues of the testcompound sprayed on the stems. The test was executed on the 3rd, 5th and7th day after spraying.

The number representing the compound in the table are the same ones asin the Example 12.

Concentration Mortality of test Test compound compound,

later 7 days later 3 days later Malathion See footnote, column 11.

EXAMPLE 16 Test for killing the larvae of rice stem borer (Chilosuppressalis) are the same ones as In the Example 12.

Concentration Test compound of test Survival compound, rate, percentpercent Control 86. 0 0. 05 7. 3 Ethyl Parathion 0.025 8. 1 ControL 26.4 II 0. 05 9. 4 0.025 14.6 Ethyl Parathion 0.025 2.8 Control 48. 8 II0.05 1.0 0. 025 6.9 Ethyl Parathion 4 0. 05 3. 3

See footnote, column 11.

EXAMPLE 17 Spray test to adult female houseflies (Musca domestica) Testinsects were put in cages by twenty insects per cage, and 5 millilitersof kerosene solution of each of ll 12 I test compounds were sprayed overthe insects in the cage For the purpose of giving those skilled in theart a at the rate of milliliters per cage. The percentage of betterunderstanding of the present invention, the followknocked-downhousefiies was observed at each time ing illustrative examples ofpresently-preferred embodishown in the table after spraying. ments ofthe compositions containing phosphoric acid The numbers representing thecompounds in the table 5 esters. In these examples, parts are by weight.are the same ones as in the Example 12.

Concentration Percentage of knocked-down housefiies after spraying(minutes) Test of test compound compound,

percent 5O 60 I 0. 05 0 5.0 25.0 00.0 65.0 70.0 II 0. 05 0 5.0 40.0 55.005.0 80.0 Diazinon 0. 03 0 5.0 50.0 00.0 85.0 85.0 Malathion 0. 05 0 05. 0 20. 0 35. 0 50. 0

See footnote.

EXAMPLE 18 EXAMPLE 20 T est for residual action 07 test compounds toadult 20 A POWder Comprising 2 Parts of Y female houseflies (Muscadomestica) methoxy-4-cyanophenyl)phosphorothioate and 98 parts of talc,according to the invention, is useful in killing in- One milliliter ofacetone solution of each of the test sects compounds was dropped on aPetri dish. After the EXAMPLE 21 dropped solution in the dish dried,twenty insects were set free in the dish. At each time as shown in thetable 25 An emulsion comprising 25 parts of O-ethyl-O-(2- after theinsects were set, knocked-down housefiies were ethoxy 4cyanophenyl)paratolylphosphonothioate, l0 counted. parts of alkylsulfate, 15 parts of polyoxyethylenephenyl- The numbers representing thecompounds in the table ether and 50 parts of xylene, according to theinvention, are the same ones as in the Example 12. is useful in killingmites.

Percentage of knocked-down housefiies after spraying (hours) TestConcentration of test Days after compound compound, percent thetreatment I 0.05 (7.85 ,i .lcm. 0 1.7 8.3 33.3 58.3 73.3 90.0 1 1.7 1.71.7 1.7 21.7 50.0 3 0 0 0 1.7 0.7 150 II 0.05 (7.85 g./cm. 0 1.7 28.341.7 78.3 95.0 100 1 0 20.0 25.0 30.0 03.3 05.0 3 0 1.7 21.7 31.7 50.783.3 Malathionh-.. 0.01 (1.57 g./0m. 0 0 1.7 25.0 55.0 75.0 81.4 1 0 1.730.7 68.3 75.0 00.7 3 0 1.7 0 5.0 8.3 10.7

See footnote.

EXAMPLE l9 EXAMPLE 22 Test of toxicity male Ge.rman Cockroaches A powdercomprising 2 parts of O-methyl-O-(Z-mea e a germamca) thoxy 4cyanophenyl)paraanisylphosphonothioate, 5 The filter paper of 9centimeters in diameter was treated parts of bentonite and 97 parts oftalc, according to the with 1 milliliter of acetone solution of each ofthe test invention, is useful in killing nematoda. compounds. After thepaper dried, it was set on the bottom of glass jar of 9 centimeters indiameters and 7 centi- EXAMPLE 23 meters in depth. Fifteen cockroacheswere driven into one jar. The inside wall of the jar was spread with alittle amount of butter to prevent the escape of the insects. Themortality was observed after 24 hours.

The numbers representing the compound in the table are the same ones asin the Example 12.

A Wetting powder comprising 2 parts of 0,0-dime-thyl-O-(2-methoxy-4-cyanophenyl)phosphorothioate, 4 parts of sodiumligninsulfonate, 4 parts of polyoxyethylenealkylarylether, 3 parts ofwhite carbon and 69 parts of clay, according to the invention, is usefulin killing insects.

Having thus disclosed the invention, what is claimed is: Test omp wel i)Mortality, 1. A phosphoric acid ester of the formula percent 157 80.8P-O CN 1010151111 9 314 100 11 1515551011 314 100 R0 157 00.0 OOHsMalathion: 0,0-dimethyl S-(1,2-dicarbethoxyethyl)dithiophosphate. 2Pestan: 0,0-diethyl S-(acetyl N-methylethylcarbamate)phosphorodighsioate. 1 hth 1N th 1 b t wherein R is alkyl of at most twocarbon atoms, and the evm: -nap y -me y car ama e. 1 4 Ethyl:0,0-diethyl-O-p-nitrophenyl thiophosphate Parathion. OCH3 group 1s oneof the POsltlons Ortho and gigithifioillzl ]1)iethyl-p-}1;1itro1p}3henyl tltrilpphosgilhate1i t meta, to the CN group y-p-mtrop eny enzeneionop osp a e. 1 DEP: Dimethy1-2,2,2-triehloro-1-hydroxyethyl phosphate.0,0 dlmethyl O y p y 8 lgiaziflotnz0,0-diethyl-O-(2-isopropy1-4-methylpyrimidyl-6)th1oh h hi nop osp 8. e.

Dieldrin:1,2,3,4,10,10-hexachloro-6,7-epoxy-l,4,4a,5,6,7,8,8a-octahy- 3-0,0 dunethyl O (3 methoxy-4-cyanophenyl)- dro-L-endo,hexo-5,8-dimethanonaphthalene. phosphorothioate.

4. A pesticidal composition which contains as an active ingredient, inminor but effective amount, a phosphoric acid ester of the formula OCHawherein R is alkyl of at most two carbon atoms, and the OCH group is inone of the positions ortho and meta to the CN group.

5. A pesticidal composition which contains as an active ingredient, inminor but effective amount, 0,0-dimethyl-O- (2-methoxy-4-cyanophenyl)phosphorothioate, and a major amount of apesticide adjuvant.

6. A pesticidal composition which contains as an active ingredient, inminor but effective amount, 0,0-dimethyl-O-(3-methoxy-4-cyanophenyl)phosphorothioate, and a major amount ofpesticide adjuvant.

7. A pesticidal composition, in concentrate form, which contains as anactive ingredient, in major amount, a phosphoric acid ester of theformula R0 5 \ll wherein R is alkyl of at most two carbon atoms, and theOCH group is in one of the positions ortho and meta to the CN group.

8.- A pesticidal composition, in concentrate form, which contains as anactive ingredient, in major amount, 0,-O-dimethylO-(2emethoxy-4-cyanophenyl)phosphorothioate.

9. A pesticidal composition, in concentrate form, which contains as anactive ingredient, in major amount, 0,0-dimethyl O-(3-methoxy-4cyanophenyl)phosphorothioate.

10. A method of killing pests which comprises applying 14 thereto, ineffective amount, a phosphoric acid ester of the formula RO S OCHB

References Cited by the Examiner UNITED STATES PATENTS 2,887,505 5/1959Blair 167-30 X 3,005,749 10/ 1961 Youngson 167-30 FOREIGN PATENTS627,817 7/1963 Belgium. 655,875 8/1951 Great Britain.

OTHER REFERENCES Nishizawa, Bull. Agr. Chem. Soc., Japan, vol. 24, No.7, pp. 744-745, 1960.

Schrader, Angew. Chem., v01. 73, No. 10, pages 331- 334, May 1961.

LEWIS GO'I'IS, Primary Examiner.

JULIAN S. LEVITT, Examiner.

RICHARD L. HUFF, Assistant Examiner.

4. A PESTICIDAL COMPOSITION WHICH CONTAINS AS AN ACTIVE INGREDIENT, INMINOR BUT EFFECTIVE AMOUNT, A PHOSPHORIC ACID ESTER OF THE FORMULA